django 中的购物车会话

Question

我使用会话来创建购物车。 我有一个产品模型和一个 Variant 模型，我在 Variant 模型中为我的产品着色和大小。这样我就可以拥有不同颜色和尺寸以及不同价格的产品。 我用 Session 创建的购物车有问题。 我遇到的问题是，如果产品有 3 种不同的颜色并且每种颜色都有不同的价格，我无法在购物车中显示价格，我不知道该怎么做。 我应该如何在模板中显示我的 Variant 模型的价格？

my Product model:
class Product(models.Model):
    name = models.CharField(max_length=200)
    price = models.IntegerField(default=0)

my Variant model:
class Variants(models.Model):
    name = models.CharField(max_length=100)
    product = models.ForeignKey(Product, on_delete=models.CASCADE, related_name='product_var',)
    size = models.ForeignKey(Size, on_delete=models.CASCADE)
    color = models.ForeignKey(Color, on_delete=models.CASCADE)
    price = models.IntegerField(default=0)

my session cart :

CART_SESSION_ID = 'cart'

class Cart:
    def __init__(self, request):
        self.session = request.session
        cart = self.session.get(CART_SESSION_ID)
        if not cart:
            cart = self.session[CART_SESSION_ID] = {}
        self.cart = cart

    def __iter__(self):
        product_ids = self.cart.keys()
        products = Product.objects.filter(id__in=product_ids)
        cart = self.cart.copy()
        for product in products:
            cart[str(product.id)]['product'] = product
            
    def add(self, product, quantity):
        product_id = str(product.id)
        if product_id not in self.cart:
            self.cart[product_id] = {'quantity': 0, 'price': str(product.total_price)}
        self.cart[product_id]['quantity'] += quantity
        self.save()

    def save(self):
        self.session.modified = True

my view:
# show cart
def cart_details(request):
    cart = Cart(request)
    return render(request, 'cart/cart_details.html', {'cart': cart, })

# add to cart
def cart_add(request, product_id):
    cart = Cart(request)
    product = get_object_or_404(Product, id=product_id)
    form = CartAddForm(request.POST)
    if form.is_valid():
        cd = form.cleaned_data
        cart.add(product=product, quantity=cd['quantity'])
    return redirect('cart:details')

my template for show product in cart:
{% for c in cart %}
    <tr>     
        <td>{{ c.product.name }}</td>
        <td>{{ c.product.price }}</td> # my problem!!!
    </tr>
{% endfor %}

Answer 1

从问题陈述中我看到，如果您将变体而不是产品存储在购物车中，问题就会消失。

代码会变成这样：

class Cart:
    def __init__(self, request):
        self.session = request.session
        cart = self.session.get(CART_SESSION_ID)
        if not cart:
            cart = self.session[CART_SESSION_ID] = {}
        self.cart = cart

    def __iter__(self):
        variant_ids = self.cart.keys()
        products = Variants.objects.filter(id__in=variant_ids)
        cart = self.cart.copy()
        for product in products:
            cart[str(variant.id)]['variant'] = variant
            
    def add(self, variant, quantity):
        variant_id = str(variant.id)
        if variant_id not in self.cart:
            self.cart[variant_id] = {'quantity': 0, 'price': str(variant.price)}
        self.cart[variant_id]['quantity'] += quantity
        self.save()

    def save(self):
        self.session.modified = True

# add to cart
def cart_add(request, variant_id):
    cart = Cart(request)
    variant = get_object_or_404(Variant, id=variant_id)
    form = CartAddForm(request.POST)
    if form.is_valid():
        cd = form.cleaned_data
        cart.add(variant=variant, quantity=cd['quantity'])
    return redirect('cart:details')

template
{% for c in cart %}
    <tr>     
        <td>{{ c.variant.name }}</td>
        <td>{{ c.variant.price }}</td>
        <td> color, etc.</td>
    </tr>
{% endfor %}

您不再需要将产品存储在购物车中，因为变体与产品表有关系。